Service meant to monitor inmates’ calls could track you, too

Thousands of jails and prisons across the United States use a company called Securus Technologies to provide and monitor calls to inmates. But the former sheriff of Mississippi County, Mo., used a lesser-known Securus service to track people’s cellphones, including those of other officers, without court orders, according to charges filed against him in state and federal court.

The service can find the whereabouts of almost any cellphone in the country within seconds. It does this by going through a system typically used by marketers and other companies to get location data from major cellphone carriers, including AT&T, Sprint, T-Mobile and Verizon, documents show.